Association of Vitamin D and Its Receptor (VDR) Gene Single Nucleotide Polymorphism (ApaI and TaqI) with Risk of Psoriasis
Introduction: Psoriasis is one of the skin related inflammatory disease that affects a much less percentage of population around the globe. Vitamin D through vitamin D receptor (VDR) also regulates the function of white blood cells in psoriasis. Mutations in VDR gene have shown abnormalities in immune responses like psoriatic arthritis. To determine the possible association between vitamin D receptor (Apa1 and Taq1) gene polymorphism and psoriasis, a case-control study was designed and conducted at Institute of Basic Medical Sciences (IBMS), Khyber Medical University (KMU) Peshawar and health units of Peshawar.
Method: This multicentre study includes 220 samples (110 cases of Psoriatic disease and 110 healthy controls). DNA was extracted using modified salting out protocol. VDR gene polymorphisms (Taq1 and Apa1) were genotyped using amplification refractory mutation system polymerase chain reaction (ARMS-PCR) method. Results were statistically analyzed.
Result: Our study showed significant association between VDR gene (Taq1, Apa1) polymorphisms and psoriasis with p-value of 0.009 (0.0019 and 0.0162) and odds ratios (95% confidence interval) for psoriasis of CC vs CT (Taq1) and AA vs AC (Apa1) were 2.963 (1.508-5.743) and 2.293 (1.22-4.246) respectively.
Conclusion: Our findings indicate that VDR gene polymorphisms (Taq1, Apa1) are significantly associated with onset and progression of psoriasis and mutations in these loci are risk factor for development of psoriasis.